Food Web Complexity and Species Diversity
TL;DR: It is suggested that local animal species diversity is related to the number of predators in the system and their efficiency in preventing single species from monopolizing some important, limiting, requisite in the marine rocky intertidal.
Abstract: It is suggested that local animal species diversity is related to the number of predators in the system and their efficiency in preventing single species from monopolizing some important, limiting, requisite. In the marine rocky intertidal this requisite usually is space. Where predators capable of preventing monopolies are missing, or are experimentally removed, the systems become less diverse. On a local scale, no relationship between latitude (10⚬ to 49⚬ N.) and diversity was found. On a geographic scale, an increased stability of annual production may lead to an increased capacity for systems to support higher-level carnivores. Hence tropical, or other, ecosystems are more diverse, and are characterized by disproportionately more carnivores.
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TL;DR: The second volume in a series on terrestrial and marine comparisons focusing on the temporal complement of the earlier spatial analysis of patchiness and pattern was published by Levin et al..
Abstract: This book is the second of two volumes in a series on terrestrial and marine comparisons, focusing on the temporal complement of the earlier spatial analysis of patchiness and pattern (Levin et al. 1993). The issue of the relationships among pattern, scale, and patchiness has been framed forcefully in John Steele’s writings of two decades (e.g., Steele 1978). There is no pattern without an observational frame. In the words of Nietzsche, “There are no facts… only interpretations.”
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4,445 citations
TL;DR: The principles of ecological succession bear importantly on the relationships between man and nature and needs to be examined as a basis for resolving man’s present environmental crisis.
Abstract: The principles of ecological succession bear importantly on the relationships between man and nature. The framework of successional theory needs to be examined as a basis for resolving man’s present environmental crisis. Most ideas pertaining to the development of ecological systems are based on descriptive data obtained by observing changes in biotic communities over long periods, or on highly theoretical assumptions; very few of the generally accepted hypotheses have been tested experimentally. Some of the confusion, vagueness, and lack of experimental work in this area stems from the tendency of ecologists to regard “succession” as a single straightforward idea; in actual fact, it entails an interacting complex of processes, some of which counteract one another.
4,419 citations
Cites background from "Food Web Complexity and Species Div..."
...…animals, which lead to the development of many mechanisms that reduce grazing --such as the development of indigestive supporting tissues (cellulose, lignin, and so on), feedback control between plants and hervibores (PIMENTEL, 1961), and increasing predatory pressure on herbivores (PAINE, 1966)....
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...Paine (1966) «Food web complexity and species diversity», American Naturalist, 100, p....
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...…Press, Orono, p. 81) H. T. ODUM (1967b) «Biological circuits and the marine systems of Texas», in Pollution and Marine Ecology, Wiley, New York, p. 99 R. T. PAINE (1966) «Food web complexity and species diversity», American Naturalist, 100, p. 65 B. C. PATTEN (1960) «Unknown Title», J. Marine....
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...(Pimentel, 1961), and increasing predatory pressure on herbivores (Paine, 1966)....
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TL;DR: In the majority of natural communities succession is frequently interrupted by major disturbances, such as fires, storms, insect plagues, etc., starting the process all over again, but if not interrupted, it eventually reaches a stage in which further change is on a small scale as individuals die and are replaced.
Abstract: The sequence of species observed after a relatively large space is opened up is a consequence of the following mechanisms. "Opportunist" species with broad dispersal powers and rapid growth to maturity usually arrive first and occupy empty space. These species cannot invade and grow in the presence of adults of their own or other species. Several alternative mechanisms may then determine which species replace these early occupants. Three models of such mechanisms have been proposed. The first "facilitation" model suggests that the entry and growth of the later species is dependent upon the earlier species "preparing the ground"; only after this can later species colonize. Evidence in support of this model applies mainly to certain primary successions and in heterotrophic succession. A second "tolerance" model suggests that a predictable sequence is produced by the existence of species that have evolved different strategies for exploiting resources. Later species will be those able to tolerate lower levels...
4,068 citations
TL;DR: The total number of species is proportional to the total range of the environment divided by the niche breadth of the species, which is reduced by unequal abundance of resources but increased by adding to the dimensionality of the niche.
Abstract: 1. There is a limit to the similarity (and hence to the number) of competing species which can coexist. The total number of species is proportional to the total range of the environment divided by the niche breadth of the species. The number is reduced by unequal abundance of resources but increased by adding to the dimensionality of the niche. Niche breadth is increased with increased environmental uncertainty and with decreased productivity. 2. There is a different evolutionary limit, L, to the similarity of two coexisting species such that a) If two species are more similar than L, a third intermediate species will converge toward the nearer of the pair. b) If two species are more different than L, a third intermediate species will diverge from either toward a phenotype intermediate between the two.
3,946 citations
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TL;DR: The address of the president of a society, founded largely to further the study of evolution, at the close of the year that marks the centenary of Darwin and Wallace's initial presentation of the theory of natural selection.
3,717 citations
3,049 citations
Book•
01 Jan 1934
TL;DR: For three-quarters of a century past more has been written about natural selection and the struggle for existence that underlies the selective process, than perhaps about any other single idea in the whole realm of Biology as discussed by the authors.
Abstract: For three-quarters of a century past more has been written about natural selection and the struggle for existence that underlies the selective process, than perhaps about any other single idea in the whole realm of Biology. We have seen natural selection laid on its Sterbebett, and subsequently revived again in the most recent times to a remarkable degree of vigor. There can be no doubt that the old idea has great survival value.
2,641 citations
TL;DR: Field observations on the daily routine and social behavior of common Indian monkeys, with special reference to the Bonnet monkey (Macaca radiata Geoff roy).
Abstract: Champion, H. G. 1936. A preliminary survey of the forest types of India and Burma. Indian Forest Records (Silviculture Series), Vol. 1, No. 1. Manson-Bahr, P. H. 1954. Manson's Tropical Diseases. 14 Ed., London, Cassell and Co. Nolte, A. 1955. Field observations on the daily routine and social behavior of common Indian monkeys, with special reference to the Bonnet monkey (Macaca radiata Geoff roy). Jour. Bombay Nat. Hist. Soc. 53: 177-184.
2,015 citations
TL;DR: In this paper, the authors attributed organic evolution mainly to the combined action of variation and the struggle for existence, primarily the competitive struggle, and argued that if competition is greatest the results for evolution are nil; where the results are greatest competition is absent.
Abstract: DARWIN attributed organic evolution chiefly to the combined action of variation and the struggle for existence, primarily the competitive struggle. This involves certain difficulties. First, the factors named tend to mutual exclusion—the more variation the less struggle. Secondly, were there no variation, competition would be intense but barren; were variation so discontinuous as to exclude competition, many certainly of the variants would perish, but others would prosper, and since there would be greater variety than under competitive conditions, there would also be more abundant life and perhaps greater evolutionary progress. Thus, where competition is greatest the results for evolution are nil; where the results are greatest competition is absent.
1,118 citations